1,720,957 research outputs found
Adoption of an auxiliary strategy to desinfect root canals and the dentinal tubules system using enterococcus faecalis bacteriophages
No full textO Enterococcus faecalis, é uma bactéria facultativa que se encontra presente em canais infectados, provocando infecções de difícil tratamento. É considerado um patógeno predominante para infecções periapicais persistentes e tem como uma de suas principais características a capacidade de formar biofilme. Além disso e de seus fatores de virulência aumentados, o E. faecalis apresenta um aumento da capacidade de aderência e aumento da resistência aos antimicrobianos. Os bacteriófagos ou fagos são um conjunto de vírus capazes de destruir bactérias específicas causadoras de doenças, invadindo células bacterianas, interrompendo seu metabolismo e causando lise celular. Anteriormente à descoberta e uso de antibióticos, a terapia por fagos era alternativa às infecções presentes. Este trabalho tem por objetivo estabelecer o potencial do uso de bacteriófagos no combate a infecções endodônticas associadas a E. faecalis como auxiliar de desinfecção do sistema de canais radiculares e sistemas de túbulos dentinários. Através de estudo piloto realizado em dentes humanos unirradiculares, seguida de visualização do biofilme por bioluminescência e pela Microscopia eletrônica de varredura (MEV), embasado na literatura existente. Os resultados mostraram-se eficazes frente ao uso de bacteriófagos e bioluminescência em relação ao E. faecalis, sendo possível notar uma redução significativa das bactérias presentes no interior do canal radicular. Este estudo nos permitiu delinear uma alternativa de ação frente ao biofilme endodôntico, complementar à ação de antimicrobianos, buscando entender melhor o funcionamento do biofilme endodôntico, dos fagos e suas aplicações na endodontia.Enterococcus faecalis, is a facultative bacterium that is present in necrotic root canals, causing infections that are difficult to treat. It is considered a predominant pathogen for persistent periapical infections and one of its main characteristics is the ability to form biofilm. In addition to that and its increased virulence factors, E. faecalis has an increased adherence capacity and increased resistance to antimicrobials. Bacteriophages or phages are a set of viruses capable of destroying specific disease-causing bacteria, invading bacterial cells, interrupting their metabolism and causing cell lysis. Previously to the discovery and use of antibiotics, phage therapy was an alternative to fight infections. The aim of this work is to establish the potential of bacteriophage use to combat endodontic infections associated with E. faecalis as an aid to disinfect the root canal system and dentinal tubule systems. The literature review was supplemented by a pilot study with uniradicular human teeth, followed by biofilm visualization through bioluminescence and scanning electron microscopy (SEM). The results suggested that the use of bacteriophages and bioluminescence may be effective against E. faecalis, being possible to notice a significant bacterial reduction present inside the root canal. This study allowed us to outline an alternative action against endodontics biofilm, complementary to the antimicrobials action, seeking to better understand the functioning of endodontics biofilm, phages and their applications in endodontics
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
CLINICAL VISUALIZATION OF ENTEROCOCCUS FAECALIS ENDOODONTIC BIOFILM THROUGH FLUORESCENCE USING TWO FLUOROPHORS
No full textSome bacteria, such as Enterococcus faecalis, are more resistant to endodontic procedures, being able to survive in the root canal system. Bacteria remaining inside the root canals, can lead to persistent infections, unsuccessful treatments or even tooth extraction. There is a great difficulty in clinically identifying the biofilm and bacteria within the root canal system. Thus, fluorescence rises as a new method to reduce the problem of clinical visualization of the endodontic infection. This study evaluated, by means of fluorescence and the use of fluorophores, the presence of Enterococcus faecalis inside the root canals. Eighteen bovine teeth, with a single canal, were selected. Teeth were decoronate, close to the cementoenamel junction, with a length equal to 16mm. Longitudinal grooves were made on the buccal and palatal surfaces of the samples and cleaning and preparation was performed with ultrasound. Root canals were infected with Enterococcus faecalis and incubated for 29 days for biofilm development, with renewal of the culture medium every 48 hours. After this period, teeth were divided into 3 groups: negative control, calcein group and qubit protein group. Teeth were clinically visualized using the ReVeal system, consisting in a 2.5x magnifying glass with an Ultraviolet photophore, allowing the observation of the fluorophores effectiveness in canals infected with Enterococcus faecalis. It was observed that both fluorophores were effective in the presence of bacteria. Negative control group did not fluoresce. Calcein had greater luminosity but showed light scattering. Qubit protein had an uniform luminescence, without image scattering
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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